The present invention relates to the field of inkjet recording for forming an image on a recording medium by means of an inkjet recording method, and more specifically to an image recording device and image recording method for correcting the density non-uniformity that occurs due to the recording characteristics of a recording element and recording an image.
One method for recording an image on a recording medium is to discharge ink drops from an inkjet head so as to form an image.
In this inkjet recording method, ink drops are discharged from a plurality of ink discharge ports, resulting in the problem of density non-uniformity of the recorded image caused by the recording characteristics (depositing position errors, variance in the volume of supplied ink, etc.) of each recording element having an ink discharge port. This problem is particularly problematic when using a single pass inkjet method that fixes a line-type inkjet head so that it is stationary and feeds a recording medium in one direction once so as to record an image on the entire surface of the recording medium.
Methods for correcting this density non-uniformity include a method of changing discharge drive conditions in accordance with density non-uniformity and adjusting the dot diameter and dot density on each recording element, and a method of correcting image data in accordance with density non-uniformity so as to ensure that the image to be recorded will not be affected by the density non-uniformity.
The method of changing discharge drive conditions involves changing the ink drops discharged from the inkjet head, resulting in limitations on the inkjet head drive system and degree of correction at the time of implementation. Conversely, the method of correcting image data in accordance with density non-uniformity involves correcting the image data while leaving the ink drops actually discharged from the inkjet head as is, i.e., without changing the inkjet head itself (that is, without making any physical changes) This latter system results in the advantage of high flexibility.
Additionally, JP2942048 discloses an image forming device that forms an image by moving a recording head, which has a plurality of recording elements, and a recording medium relatively to each other in a direction differing from the disposed direction of the recording head, the image forming device comprising: first correcting means configured to selectively provide instructions on the recording characteristics of each element of the recording head to each of a plurality of density regions; second correcting means configured to correct a density signal based on the recording characteristics instructed by the first correcting means; and selecting means configured to select the recording characteristics to be instructed by the first correcting means in accordance with the density region affiliated with the density signal corresponding to each recording element.